Semidefinite programs are convex optimization problems involving a linear objective
function and a domain of positive-semidefinite matrices. Over the past two decades, they …

We consider the distribution of secret keys, both in a bipartite and a multipartite (conference)
setting, via a quantum network and establish a framework to obtain bounds on the …

The Bennett-Brassard 1984 (BB84) protocol is the most widely implemented quantum key
distribution (QKD) scheme. However, despite enormous theoretical and experimental efforts …

The goal of quantum key distribution (QKD) is to establish a secure key between two parties
connected by an insecure quantum channel. To use a QKD protocol in practice, one has to …

Finite key analysis of quantum key distribution (QKD) is an important tool for any QKD
implementation. While much work has been done on the framework of finite key analysis, the …

Measurement-device-independent quantum key distribution (MDIQKD) is a revolutionary
protocol since it is physically immune to all attacks on the detection side. However, the …

Quantum key distribution (QKD), which theoretically provides unconditional secure
communication, has developed rapidly in the past decades. However, the practical QKD …

Large-scale quantum communication networks are still a huge challenge due to the rate-
distance limit of quantum key distribution (QKD). Recently, twin-field (TF) QKD has been …

Controlling the energy of unauthorized light signals in a quantum cryptosystem is an
essential criterion for implementation security. Here, we propose a passive optical power …

Twin-field quantum key distribution (TF-QKD) and its variant protocols are highly attractive
due to the advantage of overcoming the rate-loss limit for secret key rates of point-to-point …